Evaporator with cool storage function

ABSTRACT

An evaporator with a cool storage function includes a plurality of flat refrigerant flow tubes spaced apart from one another, and a plurality of flat cool storage material containers each of which contains a cool storage material and is disposed on one side of the corresponding refrigerant flow tube, and is brazed to the corresponding refrigerant flow tube. The cool storage material container includes a container body brazed to the corresponding refrigerant flow tube, and an internal-volume-increasing portion which extends downstream from the container body, which projects downstream from the refrigerant flow tube, and which is greater in dimension in a thickness direction than the container body. An inner fin extending from the container body to the internal-volume-increasing portion is disposed in the cool storage material container. This evaporator is suitable for a refrigeration cycle which constitutes a car air conditioner.

BACKGROUND OF THE INVENTION

The present invention relates to an evaporator with a cool storagefunction for use in a car air conditioner for a vehicle in which anengine serving as a drive source for a compressor is temporarily stoppedwhen the vehicle is stopped.

Herein and in the appended claims, the upper side and lower side ofFIGS. 1 and 2 will be referred to as “upper” and “lower,” respectively.

In recent years, in order to protect the environment and improve fuelconsumption of automobiles, there has been proposed an automobiledesigned to automatically stop the engine when the automobile stops, forexample, so as to wait for a traffic light to change.

Incidentally, an ordinary car air conditioner has a problem in that,when an engine of an automobile in which the air conditioner is mountedis stopped, a compressor driven by the engine is stopped, and supply ofrefrigerant to an evaporator stops, whereby the cooling capacity of theair conditioner sharply drops.

As one measure to solve such a problem, imparting a cool storagefunction to the evaporator has been considered, to thereby enablecooling of a vehicle compartment by making use of cool stored in theevaporator, when the compressor stops as a result of stoppage of theengine.

An evaporator having a cool storage function has been proposed (seeJapanese Patent No. 4043776). The proposed evaporator includes aplurality of sets each including two flat refrigerant flow tubes whosewidth direction coincides with an air flow direction and which arespaced apart from one another in the air flow direction, the pluralityof sets being disposed at intervals in a direction perpendicular to thewidth direction of the refrigerant flow tubes. A flat cool storagematerial container whose width direction coincides with the air flowdirection and which is filled with a cool storage material is disposedon one side of each set including two refrigerant flow tubes such thatthe cool storage material container extends over the refrigerant flowtubes adjacent to each other in the air flow direction, and is brazed tothe refrigerant flow tubes. The cool storage material container has aconstant dimension in the thickness direction over the entire coolstorage material container. Assemblies each composed of a set ofrefrigerant flow tubes arranged in the air flow direction and a coolstorage material container brazed to the set of refrigerant flow tubesare disposed at intervals in the direction perpendicular to the widthdirection of the refrigerant flow tubes. A space between adjacentassemblies serves as an air-passing clearance, and an outer fin isdisposed in the air-passing clearance and is brazed to the correspondingrefrigerant flow tubes and the corresponding cool storage materialcontainer.

In the case of the evaporator having a cool storage function disclosedin the publication, when refrigerant of low temperature flows throughthe refrigerant flow tubes, cool is stored in the cool storage materialwithin the cool storage material container.

However, in the case of the evaporator having a cool storage functiondisclosed in the publication, when an increase in the amount of the coolstorage material in the cool storage material container is desired inorder to improve the cool storage performance, the lengths of the coolstorage material containers and the refrigerant flow tubes must beincreased, and the container height (dimension with respect to thethickness direction) of the cool storage material containers must beincreased over the entirety thereof. However, when the lengths of thecool storage material containers and the refrigerant flow tubes areincreased, the size of the heat exchange core section of the evaporatorincreases, with a resultant increase in weight and deterioration inspace saving performance. Moreover, when the container height of thecool storage material container is increased over the entirety thereof,a longer time is needed so as to cool the cool storage material.Therefore, cooling performance at the time of start of cooling operationdrops. Further, when the container height of the cool storage materialcontainers is increased over the entirety thereof without changing thedimension of the heat exchange core section of the evaporator with acool storage function, the air passage area of each air-passingclearance decreases, and air passage resistance increases, whereby thecooling performance of the evaporator drops.

SUMMARY OF THE INVENTION

An object of the present invention is to solve the above problems and toprovide an evaporator with a cool storage function whose size and weightcan be reduced as compared with the evaporator with a cool storagefunction described in Japanese Patent No. 4043776, which can efficientlycool a cool storage material, and which can suppress an increase in airpassage resistance.

To fulfill the above object, the present invention comprises thefollowing modes.

1) An evaporator with a cool storage function comprising a plurality offlat refrigerant flow tubes disposed in parallel such that therefrigerant flow tubes extend vertically, the width direction of therefrigerant flow tubes coincides with an air flow direction, and therefrigerant flow tubes are spaced apart from one another, and aplurality of flat cool storage material containers each of whichcontains a cool storage material and is disposed on one side of thecorresponding refrigerant flow tube such that the cool storage materialcontainer extends vertically, the width direction of the cool storagematerial container coincides with the air flow direction, and the coolstorage material container is in thermal contact with the correspondingrefrigerant flow tubes, wherein

each of the cool storage material containers includes a container bodyin thermal contact with the corresponding refrigerant flow tube, and aninternal-volume-increasing portion which extends from the container bodytoward the upstream side or downstream side with respect to the air flowdirection, which projects outward, with respect to the air flowdirection, from the refrigerant flow tube, and which is greater indimension in a thickness direction than the container body; and

each of the cool storage material containers includes an inner findisposed therein and extending from the container body to theinternal-volume-increasing portion.

2) An evaporator with a cool storage function according to par. 1),wherein the interiors of the cool storage material containers areconnected with one another at the internal-volume-increasing portionsthereof.

3) An evaporator with a cool storage function according to par. 2),wherein the interiors of all the cool storage material containers areconnected with one another.

4) An evaporator with a cool storage function according to par. 1),wherein the inner fin is a corrugated fin having crest portionsextending in the air flow direction, trough portions extending in theair flow direction, and connection portions connecting the crestportions and the trough portions.

5) An evaporator with a cool storage function according to par. 1),wherein the inner fin is a staggered fin composed of a plurality of wavystrips which are arranged in the air flow direction and are unitarilyconnected to one anther, each of the strips having crest portionsextending in the air flow direction, trough portions extending in theair flow direction, and connection portions connecting the crestportions and the trough portions, wherein the crest portions and troughportions of one of two strips adjacent to each other in the air flowdirection are vertically shifted in position from those of the other ofthe two strips.

6) An evaporator with a cool storage function according to par. 4) or5), wherein the inner fin has a constant fin height over the entirety ofthe inner fin, the fin height being equal to the height of the interiorof the container body of the cool storage material container and lessthan the height of the interior of the internal-volume-increasingportion.

7) An evaporator with a cool storage function according to par. 1),wherein the refrigerant flow tubes and the cool storage materialcontainers are formed separately; a plurality of assemblies eachcomposed of a refrigerant flow tube and a cool storage materialcontainer whose container body is brazed to the refrigerant flow tubeare disposed at intervals in a direction perpendicular to the widthdirection of the refrigerant flow tubes; spaces each formed betweenadjacent assemblies serve as air-passing clearances; outer fins aredisposed in the air-passing clearances; portions of the outer fins onthe side toward the internal-volume-increasing portions of the coolstorage material containers project outward, with respect to the airflow direction, from the refrigerant flow tubes; and the outer fins arebrazed to opposite surfaces of the internal-volume-increasing portionsof the cool storage material containers.

8) An evaporator with a cool storage function according to par. 7),wherein the refrigerant flow tube of each of the assembly comprises aplurality of refrigerant flow tubes disposed such that the refrigerantflow tubes are spaced apart from each other in the air flow direction;and the container body of the cool storage material container of eachassembly is disposed to extend over and is brazed to all the refrigerantflow tubes of the assembly.

9) An evaporator with a cool storage function according to par. 1),wherein a portion of each cool storage material container on thedownstream side with respect to the air flow direction projects outward,with respect to the air flow direction, from the refrigerant flow tubes;and the internal-volume-increasing portion is provided on the portion ofthe cool storage material container that projects from the refrigerantflow tubes.

According to the evaporator with a cool storage function of par. 1) to9), each of the cool storage material containers includes a containerbody in thermal contact with the refrigerant flow tubes, and aninternal-volume-increasing portion which extends from the container bodytoward the upstream side or downstream side with respect to the air flowdirection, which projects outward, with respect to the air flowdirection, from the refrigerant flow tube, and which is greater indimension in a thickness direction than the container body. Therefore,the amount of the cool storage material charged into the cool storagematerial containers can be increased without increasing the lengths ofthe refrigerant flow tubes and the cool storage material containers, orincreasing the container height (the dimension in the thicknessdirection) of the cool storage material containers over the entiretythereof, as in the evaporator with a cool storage function described inJapanese Patent No. 4043776. Accordingly, the size and weight of theevaporator can be reduced, as compared with the evaporator with a coolstorage function described in Japanese Patent No. 4043776 in which thecontainer height of the cool storage material containers is constantover the entirety thereof. Moreover, the time required to cool the coolstorage material can be shortened as compared with the case where thecontainer height is increased in the evaporator with a cool storagefunction described in Japanese Patent No. 4043776 in which the containerheight of the cool storage material containers is constant over theentirety thereof. Therefore, a drop in the cooling performance at thestart of cooling operation is suppressed. In addition, since an innerfin extending from the container body to the internal-volume-increasingportion is disposed in each cool storage material container, the coolstorage material within the internal-volume-increasing portion is cooledquickly. Accordingly, the cool storage material within the cool storagematerial containers can be cooled efficiently.

Furthermore, the internal-volume-increasing portion extends from thecontainer body toward the upstream side or downstream side with respectto the air flow direction and projects outward, with respect to the airflow direction, from the refrigerant flow tube. Therefore, even in thecase where a plurality of assemblies each composed of a refrigerant flowtube and a cool storage material container whose container body is inthermal contact with the refrigerant flow tube are disposed at intervalsin a direction perpendicular to the width direction of the refrigerantflow tubes, and spaces each formed between adjacent assemblies serve asair-passing clearances, the amount of the cool storage material chargedinto the cool storage material containers can be increased withoutchanging the dimensions of the heat exchange core section. Accordingly,a decrease in the areas of the air-passing clearance can be suppressedas compared with the evaporator with a cool storage function describedin Japanese Patent No. 4043776, whereby an increase in air passageresistance can be suppressed, and, as a result, a drop in coolingperformance can be prevented.

According to the evaporator with a cool storage function of par. 2), theinteriors of the cool storage material containers communicate with oneanother at the internal-volume-increasing portions thereof. Therefore,through formation of a cool-storage-material charging opening in theinternal-volume-increasing portion of one cool storage materialcontainer and an air bleeding opening in the internal-volume-increasingportion of another cool storage material container, an operation ofcharging the cool storage material into the mutually connected coolstorage material containers becomes easier.

According to the evaporator with a cool storage function of par. 4) to6), when the cool storage material is charged from theinternal-volume-increasing portion into the cool storage materialcontainer, the cool storage material having entered theinternal-volume-increasing portion of the cool storage materialcontainer reaches the container body via spaces between adjacentconnection portions of the inner fin. Therefore, the operation ofcharging the cool storage material can be readily performed.

According to the evaporator with a cool storage function of par. 7), aplurality of assemblies each composed of a refrigerant flow tube and acool storage material container whose container body is brazed to therefrigerant flow tube are disposed at intervals in a directionperpendicular to the width direction of the refrigerant flow tubes;spaces each formed between adjacent assemblies serve as air-passingclearances; outer fins are disposed in the air-passing clearances;portions of the outer fins on the side toward theinternal-volume-increasing portions of the cool storage materialcontainers project outward, with respect to the air flow direction, fromthe refrigerant flow tubes; and the outer fins are brazed to oppositesurfaces of the internal-volume-increasing portions of the cool storagematerial containers. Therefore, when a compressor stops as a result ofstoppage of an engine, the cool stored in the cool storage materialwithin the internal-volume-increasing portion of each cool storagematerial container is transferred from the opposite side surfaces of theinternal-volume-increasing portion to air passing through theair-passing clearance via the fins brazed to the opposite side surfacesof the internal-volume-increasing portions. Accordingly, cool radiationperformance is improved.

According to the evaporator with a cool storage function of par. 9), theinternal-volume-increasing portion is provided on the downstream side ofthe container body. Therefore, the internal-volume-increasing portioninto which a large amount of the cool storage material is charged ispresent at a position at which air passing through the air-passingclearances has a lowered temperature. Accordingly, the cool storagematerial within the cool storage material containers can be cooledefficiently, whereby cool storage performance is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cut-away perspective view showing the overallstructure of an evaporator with a cool storage function according to thepresent invention;

FIG. 2 is a partially omitted enlarged sectional view taken along lineA-A of FIG. 1;

FIG. 3 is an enlarged sectional view taken along line B-B of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line C-C of FIG. 2;

FIG. 5 is a perspective view showing a plurality of cool storagematerial containers united together;

FIG. 6 is an exploded perspective view showing a single cool storagematerial container; and

FIG. 7 is an exploded perspective view corresponding to FIG. 6 andshowing a modification of the cool storage material container.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will next be described withreference to the drawings.

In the following description, the downstream side with respect to theair flow direction (a direction represented by arrow X in FIGS. 1 to 4)will be referred to as the “front,” and the opposite side as the “rear.”Further, the left-hand and right-hand sides as viewed rearward from thefront side; i.e., the left-hand and right-hand sides of FIG. 1, will bereferred to as “left” and “right,” respectively.

In the following description, the term “aluminum” encompasses aluminumalloys in addition to pure aluminum.

FIG. 1 shows the overall configuration of an evaporator with a coolstorage function according to the present invention, and FIGS. 2 to 6show the configurations of essential portions of the evaporator.

As shown in FIGS. 1 and 2, an evaporator with a cool storage function 1includes a first header tank 2 and a second header tank 3 formed ofaluminum and disposed apart from each other in the vertical directionsuch that they extend in the left-right direction; and a heat exchangecore section 4 provided between the two header tanks 2 and 3.

The first header tank 2 includes a refrigerant inlet header section 5located on the front side (downstream side with respect to the air flowdirection); and a refrigerant outlet header section 6 located on therear side (upstream side with respect to the air flow direction) andunited with the refrigerant inlet header section 5. A refrigerant inlet7 is provided at the right end of the refrigerant inlet header section5, and a refrigerant outlet 8 is provided at right end of therefrigerant outlet header section 6. The second header tank 3 includes afirst intermediate header section 9 located on the front side, and asecond intermediate header section 11 located on the rear side andunited with the first intermediate header section 9. The respectiveinteriors of the first and second intermediate header sections 9 and 11of the second header tank 3 are connected together via a communicationmember 12 which extends across and is brazed to the right ends of theintermediate header sections 9 and 11 and which has a flow passageformed therein.

As shown in FIGS. 1 to 4, the heat exchange core section 4 includes aplurality of sets 14 each composed of a plurality of (two in the presentembodiment) flat refrigerant flow tubes 13 formed of aluminum extrudate.The refrigerant flow tubes 13 extend in the vertical direction, and aredisposed such that their width direction coincides with the front-reardirection and they are spaced apart from each other in the front-reardirection. The plurality of sets 14 are disposed at predeterminedintervals in the left-right direction (the direction perpendicular tothe width direction of the refrigerant flow tubes 13). A flat coolstorage material container 15 formed of aluminum and filled with a coolstorage material (not illustrated) is disposed on one side (the leftside surface in the present embodiment) of each set 14 composed of tworefrigerant flow tubes 13. The cool storage material container 15extends in the vertical direction, and is disposed such that its widthdirection coincides with the front-rear direction. The cool storagematerial container 15 extends over the two refrigerant flow tubes 13 ofeach set 14.

Upper end portions of the front refrigerant flow tubes 13 are connectedto the refrigerant inlet header section 5, and lower end portions of thefront refrigerant flow tubes 13 are connected to the first intermediateheader section 9. Further, upper end portions of the rear refrigerantflow tubes 13 are connected to the refrigerant outlet header section 6,and lower end portions of the rear refrigerant flow tubes 13 areconnected to the second intermediate header section 11. Thus, there areformed a plurality of assemblies 16 each composed of one set 14including the two refrigerant flow tubes 13 arranged in the front-reardirection, and the cool storage material container 15 disposed to extendover the two refrigerant flow tubes 13 of each set 14. The plurality ofassemblies 16 are disposed at predetermined intervals in the left-rightdirection. Spaces each formed between adjacent assemblies 16 serveair-passing clearances 17. Outer fins 18 formed of aluminum are disposedin the air-passing clearances 17, and are brazed to the correspondingrefrigerant flow tubes 13 and the corresponding cool storage materialcontainers 15. Further, the outer fin 18 formed of aluminum is disposedon the outer sides of the assemblies 16 (each composed of therefrigerant flow tubes 13 of each set 14 and the corresponding coolstorage material container 15) located at the left and right ends,respectively. The right end outer fin 18 is brazed to the front and rearrefrigerant flow tubes 13 located at the right end, and the left endouter fin 18 is brazed to the cool storage material container 15 locatedat the left end. Notably, each of the outer fins 18 is a corrugated finhaving crest portions extending in the front-rear direction, troughportions extending in the front-rear direction, and connection portionsconnecting the crest portions and the trough portions. A side plate 19formed of aluminum is disposed on the outer side of each of the outerfins 18 located at the left and right ends, respectively, and is brazedto the corresponding outer fin 18. Thus, the air-passing clearance 17 isalso formed between the side plate 19 at the left end and the assembly16 at the left end and between the side plate 19 at the right end andthe assembly 16 at the right end.

As shown in FIGS. 2 to 5, each cool storage material container 15includes a container body 21 and an internal-volume-increasing portion22. The container body 21 is located rearward of the front edges of therefrigerant inlet header section 5 and the first intermediate headersection 9, and is brazed to the front and rear refrigerant flow tubes 13of the corresponding set 14. The internal-volume-increasing portion 22extends from the front edge of the container body 21 such that thevolume-increasing portion 22 projects frontward from the front edges ofthe refrigerant inlet header section 5 and the first intermediate headersection 9. The dimension of the internal-volume-increasing portion 22 asmeasured in the thickness direction (left-right direction) is greaterthan that of the container body 21. The dimension of the container body21 as measured in the left-right direction is constant over the entiretythereof. The dimension of the internal-volume-increasing portion 22 asmeasured in the left-right direction is equal to the sum of a tubeheight, which is the dimension of the refrigerant flow tubes 13 asmeasured in the thickness direction (left-right direction) and thedimension of the container body 21 of each cool storage materialcontainer 15 as measured in the thickness direction. Theinternal-volume-increasing portion 22 is swelled rightward only inrelation to the container body 21, and the left side surface of theinternal-volume-increasing portion 22 is flush with the left sidesurface of the container body 21.

An inner fin 23 which is formed of aluminum and which extends from therear edge of the container body 21 to the front end of theinternal-volume-increasing portion 22 is disposed in each cool storagematerial container 15 such that the inner fin 23 extends oversubstantially the entire vertical length of the container body 21. Theinner fin 23 is a corrugated fin having crest portions 23 a extending inthe front-rear direction, trough portions 23 b extending in thefront-rear direction, and connection portions 23 c connecting the crestportions 23 a and the trough portions 23 b (see FIG. 6). The fin heightof the inner fin 23 is constant over the entire inner fin 23. The innerfin 23 is brazed to the inner surfaces of the left-side walls of thecontainer body 21 and the internal-volume-increasing portion 22 of thecool storage material container 15, and is brazed to the inner surfaceof the right-side wall of the container body 21.

Upper and lower end portions of the internal-volume-increasing portion22 of each cool storage material container 15 project upward anddownward, respectively, from the upper and lower ends of the containerbody 21. Each of the projecting portions of theinternal-volume-increasing portion 22 has left and right tank-formingportion 25 swelled outward with respect to the left-right direction. Thetank-forming portion 25 of the internal-volume-increasing portions 22 ofadjacent cool storage material containers 15 are brazed to each other,whereby all the cool storage material containers 15 are united. Further,a communication hole 26 formed in a swelled end wall portion of each ofthe tank-forming portion 25 establishes communication between theinteriors of the tank-forming portion 25 of theinternal-volume-increasing portions 22 of adjacent cool storage materialcontainers 15. The upper tank-forming portion 25 of theinternal-volume-increasing portions 22 of all the cool storage materialcontainers 15 form an upper communication tank 27, and the lowertank-forming portion 25 of the internal-volume-increasing portions 22 ofall the cool storage material containers 15 form a lower communicationtank 27. Thus, the interiors of all the cool storage material containers15 are connected together via the upper and lower communication tanks27. Although not illustrated, preferably, a cool-storage-materialcharging opening is formed in one of the upper and lower communicationtanks 27, and an air-bleeding opening is formed in the other of theupper and lower communication tanks 27. A cool storage material ischarged into all the cool storage material containers 15 via thecool-storage-material charging opening. In this case, the cool storagematerial first enters the internal-volume-increasing portion 22 of eachcool storage material container 15, and then enters the container body21 thereof through spaces between the adjacent connection portions 23 cof the corresponding inner fin 23. After the cool storage material ischarged into the cool storage material containers 15, thecool-storage-material charging opening and the air-bleeding opening areclosed by appropriately means. Examples of the cool storage material tobe charged into the cool storage material containers 15 include awater-based cool storage material and a paraffin-based cool storagematerial having an adjusted freezing point of about 3 to 10° C. Further,preferably, the amount of the cool storage material charged into thecool storage material containers 15 is determined so that the coolstorage material fills all the cool storage material containers 15 up totheir upper ends.

As shown in FIG. 6, each cool storage material container 15 is composedof two generally rectangular, vertically elongated aluminum plates 28and 29 brazed together along their peripheral edge portions. Both thealuminum plates 28 and 29 are formed from an aluminum brazing sheethaving a brazing material layer on each of opposite sides thereof, andhave the same external shape when they are viewed from the left andright sides, respectively. The left-hand aluminum plate 28, whichpartially constitutes the cool storage material container 15, includes afirst swelled portion 31 for forming the container body 21, a secondswelled portion 32 for forming the internal-volume-increasing portion22, and third swelled portions 33 for forming the tank-forming portions25. The first swelled portion 31 accounts for the greater part of thealuminum plate 28, excluding a front portion thereof, and is swelledleftward. The second swelled portion 32, which extends frontward fromthe first swelled portion 31, is swelled leftward, and has the sameswelling height as the first swelled portion 31. The third swelledportions 33 are provided at the upper and lower ends of the secondswelled portion 32, are swelled leftward, and have a swelling heightgreater than that of the second swelled portion 32. The above-mentionedcommunication holes 26 are formed on the swelled end walls of the thirdswelled portions 33 of the left-hand aluminum plate 28 of each coolstorage material container 15, excluding the cool storage materialcontainer 15 at the left end.

The right-hand aluminum plate 29, which partially constitutes the coolstorage material container 15, includes a flat portion 34 for formingthe container body 21, a first swelled portion 35 for forming theinternal-volume-increasing portion 22, and second swelled portions 36for forming the tank-forming portions 25. The flat portion 34 accountsfor the greater part of the aluminum plate 29, excluding a front portionthereof. The first swelled portion 35, which extends frontward from theflat portion 34, is swelled rightward. The second swelled portions 36are provided at the upper and lower ends of the first swelled portion35, are swelled rightward, and have a swelling height greater than thatof the first swelled portion 35. The above-mentioned communication holes26 are formed on the swelled end walls of the second swelled portions 36of the right-hand aluminum plate 29 of each cool storage materialcontainer 15, excluding the cool storage material container 15 at theright end.

The two aluminum plates 28 and 29 are assembled and brazed together sothat the openings of the swelled portions 32 and 35 face each other, theopenings of the swelled portions 33 and 36 face each other, and theopening of the first swelled portion 31 is closed by the flat portion34. Thus, the cool storage material container 15 is formed. The tankformation portions 25 of two adjacent cool storage material containers15 are brazed to each other such that the communication holes 26 of thethird swelled portions 33 communicate with the communication holes 26 ofthe second swelled portions 36.

A front portion of each outer fin 18 projects frontward from the frontrefrigerant flow tubes 13. A portion of the outer fin 18, which portionprojects frontward from the front refrigerant flow tubes 13, is brazedto the left side surface of the internal-volume-increasing portion 22 ofthe cool storage material container 15 located on the right side of theouter fin 18, and is brazed to the right side surface of theinternal-volume-increasing portion 22 of the cool storage materialcontainer 15 located on the left side of the outer fin 18.

The above-described evaporator 1 with a cool storage functionconstitutes a refrigeration cycle, in combination with a compressordriven by an engine of a vehicle, a condenser (refrigerant cooler) forcooling the refrigerant discharged from the compressor, and an expansionvalve (pressure-reducing unit) for reducing the pressure of therefrigerant having passed through the condenser. The refrigeration cycleis installed, as a car air conditioner, in a vehicle, such as anautomobile, which temporarily stops the engine, which serves as a drivesource of the compressor, when the vehicle is stopped. In the case ofsuch an car air conditioner, when the compressor is operating, lowpressure, two-phase refrigerant (a mixture of vapor refrigerant andliquid refrigerant) having been compressed by the compressor and havingpassed through the condenser and the expansion valve passes through therefrigerant inlet 7, and enters the inlet header section 5 of theevaporator 1. The refrigerant then passes through all the frontrefrigerant flow tubes 13, and enters the first intermediate headersection 9. The refrigerant having entered the first intermediate headersection 9 passes through the communication member 12, and enters thesecond intermediate header section 11. After that, the refrigerantpasses through all the rear refrigerant flow tubes 13, enters the outletheader section 6, and flows out via the refrigerant outlet 8. When therefrigerant flows through the refrigerant flow tubes 13, the refrigerantperforms heat exchange with air passing through the air-passingclearances 17, and flows out of the refrigerant flow tubes 13 in a vaporphase.

At that time, the cool storage material within the container body 21 ofeach cool storage material container 15 is cooled by the refrigerantflowing through the refrigerant flow tubes 13, and cool of the cooledcool storage material within the container body 21 is transferred to thecool storage material within the internal-volume-increasing portion 22of the cool storage material container 15 via the inner fin 23. Inaddition, the cool storage material within theinternal-volume-increasing portion 22 of each cool storage materialcontainer 15 is cooled by air having been cooled by the refrigerantwhile passing through the air-passing clearances 17. As a result, coolis stored in the entire cool storage material within the cool storagematerial container 15.

When the compressor stops, the cool stored in the cool storage materialwithin the container body 21 and the internal-volume-increasing portion22 of each cool storage material container 15 is transferred to the leftside walls of the container body 21 and the internal-volume-increasingportion 22 via the corresponding inner fin 23, and then transferred toair passing through the corresponding air-passing clearance 17 via theouter fin 18 brazed to the left side surface of the cool storagematerial container 15. Furthermore, the cool stored in the cool storagematerial within the container body 21 of each cool storage materialcontainer 15 is transferred to the right side wall of the container body21 via the corresponding inner fin 23, and then transferred from theright side surface of the container body 21 to air passing through thecorresponding air-passing clearance 17 via the corresponding refrigerantflow tubes 13 and the outer fin 18 brazed to the refrigerant flow tubes13. Moreover, the cool stored in the cool storage material within theinternal-volume-increasing portion 22 of each cool storage materialcontainer 15 is transmitted from the right side surface of theinternal-volume-increasing portion 22 to the air passing through thecorresponding air-passing clearances 17 via the outer fin 18 brazed tothe right side surface of the internal-volume-increasing portion 22.Accordingly, even when the temperature of wind having passed through theevaporator 1 increases, the wind is cooled, so that a sharp drop in thecooling capacity can be prevented.

In the above-described embodiment, each of the refrigerant flow tubes ofthe evaporator with a cool storage function may be provided in a flathollow body formed by two aluminum plates brazed together along theirperipheral edge portions, as in the case of a so-called laminate-typeevaporator. That is, each of the refrigerant flow tubes may be formedbetween the two aluminum plates which were swelled so as to constitute aflat hollow body.

FIG. 7 shows a modification of the cool storage material container.

In the case of a cool storage material container 40 shown in FIG. 7, astaggered inner fin 41 formed of aluminum is disposed in the coolstorage material container 40 such that the inner fin 41 extends fromthe rear end of the container body 21 to the front end of theinternal-volume-increasing portion 22, and extends over substantiallythe entire vertical length of the container body 21. The inner fin 41 isformed by means of unitarily connecting a plurality of wavy strips 42which are arranged in the air flow direction and each of which has crestportions 42 a extending in the front-rear direction (the air flowdirection), trough portions 42 b extending in the front-rear direction,and connection portions 42 c connecting the crest portions 42 a and thetrough portions 42 b. The crest portions 42 a and trough portions 42 bof one of two strips 42 adjacent to each other in the front-reardirection are vertically shifted in position from those of the other ofthe two strips 42.

Other structures are the same as the cool storage material container 15of the above-described embodiment.

1. An evaporator with a cool storage function comprising a plurality offlat refrigerant flow tubes disposed in parallel such that therefrigerant flow tubes extend vertically, the width direction of therefrigerant flow tubes coincides with an air flow direction, and therefrigerant flow tubes are spaced apart from one another; and aplurality of flat cool storage material containers each of whichcontains a cool storage material and is disposed on one side of thecorresponding refrigerant flow tube such that the cool storage materialcontainer extends vertically, the width direction of the cool storagematerial container coincides with the air flow direction, and the coolstorage material container is in thermal contact with the correspondingrefrigerant flow tube, wherein each of the cool storage materialcontainers includes a container body in thermal contact with thecorresponding refrigerant flow tube, and an internal-volume-increasingportion which extends from the container body toward the upstream sideor downstream side with respect to the air flow direction, whichprojects outward, with respect to the air flow direction, from therefrigerant flow tube, and which is greater in dimension in a thicknessdirection than the container body; and each of the cool storage materialcontainers includes an inner fin disposed therein and extending from thecontainer body to the internal-volume-increasing portion.
 2. Anevaporator with a cool storage function according to claim 1, whereinthe interiors of the cool storage material containers are connected withone another at the internal-volume-increasing portions thereof.
 3. Anevaporator with a cool storage function according to claim 2, whereinthe interiors of all the cool storage material containers are connectedwith one another.
 4. An evaporator with a cool storage functionaccording to claim 1, wherein the inner fin is a corrugated fin havingcrest portions extending in the air flow direction, trough portionsextending in the air flow direction, and connection portions connectingthe crest portions and the trough portions.
 5. An evaporator with a coolstorage function according to claim 1, wherein the inner fin is astaggered fin composed of a plurality of wavy strips which are arrangedin the air flow direction and are unitarily connected to one anther,each of the strips having crest portions extending in the air flowdirection, trough portions extending in the air flow direction, andconnection portions connecting the crest portions and the troughportions, wherein the crest portions and trough portions of one of twostrips adjacent to each other in the air flow direction are verticallyshifted in position from those of the other of the two strips.
 6. Anevaporator with a cool storage function according to claim 4, whereinthe inner fin has a constant fin height over the entirety of the innerfin, the fin height being equal to the height of the interior of thecontainer body of the cool storage material container and less than theheight of the interior of the internal-volume-increasing portion.
 7. Anevaporator with a cool storage function according to claim 1, whereinthe refrigerant flow tubes and the cool storage material containers areformed separately; a plurality of assemblies each composed of arefrigerant flow tube and a cool storage material container whosecontainer body is brazed to the refrigerant flow tube are disposed atintervals in a direction perpendicular to the width direction of therefrigerant flow tubes; spaces each formed between adjacent assembliesserve as air-passing clearances; outer fins are disposed in theair-passing clearances; portions of the outer fins on the side towardthe internal-volume-increasing portions of the cool storage materialcontainers project outward, with respect to the air flow direction, fromthe refrigerant flow tubes; and the outer fins are brazed to oppositesurfaces of the internal-volume-increasing portions of the cool storagematerial containers.
 8. An evaporator with a cool storage functionaccording to claim 7, wherein the refrigerant flow tube of each of theassembly comprises a plurality of refrigerant flow tubes disposed suchthat the refrigerant flow tubes are spaced apart from each other in theair flow direction; and the container body of the cool storage materialcontainer of each assembly is disposed to extend over and is brazed toall the refrigerant flow tubes of the assembly.
 9. An evaporator with acool storage function according to claim 1, wherein a portion of eachcool storage material container on the downstream side with respect tothe air flow direction projects outward, with respect to the air flowdirection, from the refrigerant flow tubes; and theinternal-volume-increasing portion is provided on the portion of thecool storage material container that projects from the refrigerant flowtubes.
 10. An evaporator with a cool storage function according to claim5, wherein the inner fin has a constant fin height over the entirety ofthe inner fin, the fin height being equal to the height of the interiorof the container body of the cool storage material container and lessthan the height of the interior of the internal-volume-increasingportion.